Species Browser
Species Detail Information
Phytophthora inflata
This genus-wide phylogenetic tree contains 85 species, including Pythium vexans and Pythium undulatum as the outgroup, and was built using sequences at seven loci (approximately 8700 nucleotides), including 60S Ribosomal Protein L10, Beta Tubulin, Enolase, Heat Shock Protein 90, Large Subunit rRNA, TigA gene fusion, and Translation Elongation Factor 1 alpha (Jaime Blair et al., Fungal Genetics & Biology).The sequence alignment nexus file used to draw this tree can be downloaded by clicking the logo.
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Geological distribution
Nomenclature
This information was provided by the the Systematic Botany and Mycology Laboratory in USDA-ARS.
P. inflata Caroselli & Tucker 1949 (Oomycetes, Pythiales)
Notes: Cooke et al. (2000) suggested that P. inflata is conspecific with P. citricola, but according to Kroon et al. (2004), the two species differ in their mitochondrial DNA.
Distribution: Europe (England), North America (Canada, USA).
Substrate: Tree trunks. Also reported on twigs, leaves (Testa et al. 2005).
Disease Note: Pit canker.
Host: Ulmus spp. (Ulmaceae). Also reported on Sambucus and Syringa; and recently on Rhododendron (Testa et al. 2005).
Supporting Literature:
Cooke, D.E.L., Drenth, A., Duncan, J.M., Wagels, G., and Brasier, C.M. 2000. A molecular phylogeny of Phytophthora and related Oomycetes. Fungal Genet. Biol. 30: 17-32
Erwin, D.C., and Ribeiro, O.K. 1996. Phytophthora Diseases Worldwide. APS Press, St. Paul, Minnesota, 562 pages.
Kroon, L.P.N.M., Bakker, F.T., van den Bosch, G.B.M., Bonants, P.J.M., and Flier, W.G. 2004. Phylogenetic analysis of Phytophthora species based on mitochondrial and nuclear DNS sequences. Fungal Genet. Biol. 41: 766-782
Testa, A., Schilb, M., Lehman, J.S., Cristinzio, G., and Bonello, P. 2005. First report of P. insolita and P. inflata on Rhododendron in Ohio. Pl. Dis. 89: 1128
Updated on Jun 05, 2006
Characteristics
P. inflata is classified in group III (Stamps et al. 1990). Morphology is shown in Figure 1. See Tables 4.2 and 4.3 in Phytophthora Diseases Worldwide (Erwin and Ribeiro 1996)for tabular keys.
1. Sporangia
Sporangia are semipapillate, broad, limoniform to elongate with occasional lateral attachments, 20 to 67 µm long x 15 to 32 µm wide, average 38 x 23 µm (length-breadth ratio 1.3:1), and persistent on the stalk and form on unbranched sporangiophores (Caroselli and Tucker 1949). G. Hall et al. (1992) found sporangia to be highly variable in size with an average length-breadth ratio of 1.12:1. Sporangia germinate by external proliferation.
2. Chlamydospores
Chlamydospores are not formed although thin-walled, hyaline, intercalary hyphal swellings form in aqueous cultures.
3. Sex Organs
P. inflata is homothallic; oogonia are 30 to 43 µm in diameter, average 34 µm; antheridia are paragynous, often contorted or inflated and twisted around the oogonial stalk or irregularly lobed or branched (up to 15 x 50 µm); oospores are 26 to 39.3 µm in diameter, average 31.3 µm, with a thick wall (3 to 4 µm) and are aplerotic. The inflated antheridia are highly characteristic (G. Hall et al. 1992).
4. Growth Temperatures
Optimum temperature for growth is 25 to 30oC, and the maximum is <35oC. Information on the minimum temperature is not available.
5. Distinguishing Characteristics
The large, contorted, inflated, variously lobed or branched paragynous antheridia differentiate P. inflata from other Phytophthora species. The inflated antheridia are most readily observed in young cultures. Although Caroselli and Tucker (1949) considered P. megasperma and P. erythroseptica to be similar to P. inflata, the semipapillate nature of the sporangia places P. inflata in group III of Stamps et al. (1990), whereas the other species produce nonpapillate sporangia, thus placing them in group VI. The inflated antheridia differentiate P. inflata from certain other species in group III, such as P. citricola, which also produces paragynous antheridia and semipapillate sporangia.
*The references cited in this section can be found in the reference library.
